- Unitrends Enterprise Backup™: web-based and virtual software based appliance for backup and restoration. For really small virtualized environments ( 1TB maximum w/ local storage, or 1.5TB w/ an included cloud special offering), UNITRENDS offers UNITRENDS Free™ virtual appliance which includes unlimited number of VMs and process host sockets for vSphere and Hyper-V VM backup. It also can protect physical server "assets".